This article reviews the roles and interactions of iron, atherosclerosis, and neurodegeneration. It highlights the importance of cholesterol in promoting iron-dependent oxidative damage. An intriguing possibility is that hypercholesterolemia can increase brain iron load and both the aggregation of beta-amyloid and the ability of iron on plaques to catalyze oxidative damage. This could explain why hypercholesterolemia is a risk factor for Alzheimer's disease. Further work is necessary to study the mechanism of increased iron transport across the blood brain barrier in atherosclerosis.